Telephone-transmitter



provided with a slot d. curved in a circle,

residing at Chicago, in the county of Cook wherein like reference-letters indicate like support a horizontal rod E., whose extremis between the two electrodes, and of suspend- UNITED' STATES ,ATENT 'FFIcE.

HENRY L. BALDWINQ-o CHICAGO, ILLINOIS.

TELEPHONE-TRANSMITTER.

SPECIFICATION forming part of Letters Patent No. 526,139, dated September 18,1894.

-. Application filed January 30, 1892.

To aZZ-whom it may concern:

B e it known that I, HENRY L. BALDWIN, a citizen of the United States of America,

and State of Illinois, have invented a certain new and Improved Telephone-Transmitter,

of which the following is a specification.

Referring to the accompanying drawings,

parts, Figure l is a vertical section of the box and its contents; Fig. 2, a horizontal scction, and Fig. 3 a detached detail view.

Myinvention consists in an improved means for effecting, adjusting and maintaining working-contact between the electrodes. To this end, in any suitable transmitter-box A., provided with a suitable diaphragm 13., I mount upon the diaphragm, preferably by a holder 0, a horizontal bar 0., of compacted carbon or other material adapted to act as an electrode. Above the diaphragm I attach to the box A. two parallel brackets D. 1)., each whose center is approximately at the contactpoints of the electrodes. These two brackets ties extend through the slots 01.", and are provided with clamping nuts f. f so that the rod can be adjusted to and clamped in any desired position in said slots. From the rod E, by means of swinging dependent arms 0., I suspend a series (preferably four or five) of carbons M. in such a way that all of them will lieagainst the side of the electrode 0., and in light contact therewith, but not in contact with each other, and so that their contact pressure can, within suitable limits, be varied and adjusted by moving the rod E. to dilterent points in the slots d. The hanging arms Grare articulated loosely on the rod, and kept apart by rubber sleeves or Washers 9., arranged between them. The current traverses the wire 10., diaphragm, carbonholder, electrodes, arms G., rod E., and wire w., all of which are of suitable conducting material. The multiplicity of contact points ing arms 0., insures constant contact and enables small and light carbons m. to be used, and at the same time a large extent of contact surface to be secured, while the force of contact is readily adjusted to the utmost Serial No. 419,730. (No model.)

loud and distinct articulation, responds to tones varying between great extremes of loudness, and when once properly adjusted, requires no further care. 0., instead of being made in a continuous The bar-electrode piece of carbon, may be made up of separate carbon blocks held in a metal holderthe es "sential requisite being that the current, in

passing from bar 0. to rod E., or line, shall proceed in multiple are, or, in other words, through several independent channels, simultaneously, each having its own electrode.

For extreme delicacy of adjustment of contact-pressure, it is material thatthe arms G. be so formed that, when hanging free, they will not extend in a vertical, but in an inclined, direction, the bottoms inclining toward the diaphragm. This is accomplished, in the form here shown, by making them curved outwardly, as illustrated in Fig. 1, or in other words, by so disposing their material that their center of gravity will not come in a line drawn from their pivots to their free.

tion, in the circuit, of a horizontal bar-elect trode 0., with a series of electrodes rm, suspended by separate pendent arms G. from a horizontal rod E., adjustable in position by means of slots 01., and clamping nuts f. f substantially as described.

2. In a telephonetransmitter, a horizontal bar elect-rode mounted upon a diaphragm, in combination witha series of depending arms suspended from a horizontally adjustable rod, terminating in electrical contact points, said arms being constructed heavier upon the side opposite to the electrode, so as to (No Model.)

H. J. BANG. BLEGTRIGALLY OPERATED REGISTER FOR BARRELS, &c. No. 526,140,

Patented Sept. 18, 1894.

0., PHOTOUTHO WASHXNGTON n l: 

